// Problem: 
// Contest: 
// URL: 
// Memory Limit: 
// Time Limit: 
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#include<bits/stdc++.h>
using namespace std;
#define int long long
inline int read(){
	int s=0,w=1;
	char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
	while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
	return s*w;
}
signed main()
{
	int t=1;
//	cin>>t;
	while(t--)
	{
		int n,p;
		cin>>n>>p;
		vector<int> a(n+1),b(n+1);
		for(int i=1;i<=n;i++)
		{
			cin>>a[i];
			b[i]=a[i]-a[i-1];
		}
		for(int i=1;i<=p;i++)
		{
			int x,y,z;
			cin>>x>>y>>z;
			b[x]+=z;
			b[y+1]-=z;
		}
		int ans=INT_MAX;
		for(int i=1;i<=n;i++)
		{
			a[i]=a[i-1]+b[i];
			ans=min(ans,a[i]);
		}
		cout<<ans;
	}
	return 0;
}
